Not sure if this is related or not, but I just had to replace a plastic thermostat cap on my 190-16v. It had started to leak from the plastic 'nipple' that is the begining of a hose back to the resovoir, and the piece broke off completely when i tried to examine it. This is not a 'stressed' part in any way except incorrect anti-freeze and high temps. Just for the records, my h20 runs about 85-90, but my oil goes to 100-110. Go figure.